With all this talk of dragons, one seems to have finally been unintentionally summoned. Iraleth, Farengar, and yourself must convene at the planning room just beyond Dragonsreach Jarl's quarters located within Dragonsreach to speak with the Jarl. The Jarl gives you the Iron Helmet of Minor Destruction and the party scatters. You'll need to rendezvous with Irileth outside of town. Leave Dragonsreach and head toward the Western Watchtower, not far off from Whiterun. Irileth and her band of guards stand just outside the watchtower's ruins. A dragon has very recently laid waste to it and should still be around; as you head toward it, a dragon by the name of Mirmulnir appears.

Apparently, this dragon is quite the weakling since iron arrows can easily pierce its thick dragon hide and inflict decent damage. Hopefully, you've hung onto a bow and have a decent command of archery. Fire arrows while the dragon remains airborne. Periodically, Mirmulnir will land on the ground and breathe fire, but this also means she is within attacking range. If you have an affinity to magicka, she is particularly vulnerable to ice-based magic. With help from Irileth's men, Mirmulnir's strength will slowly ebb and finally cause her to fall.

Rummage through her carcass for a surprising number of items. Of particular note is the first of many Dragon Souls you'll collect. You'll now be able to put that Unrelenting Force you discovered earlier to good use. Now you can experiment with Shout, which can be found in your Magic menu and used as afforded by completion of its cooldown timer.

Return to Whiterun and speak to the Jarl. Brief him on what happened and mention the tidbit about Dragonborn, to which Jarl tells you about the Greybeard's summon. That booming thunder-like sound you heard as you ran toward Whiterun earlier? That was the Greybeards. The Jarl's parting words bestow you the greatest honor of the title Thane of Whiterun, as well as his eternal friendship.

Tip: You can abuse your power to basically delete one unlawful offense. If you're caught multiple times, however, even your swank title won't keep the hammer from falling down on you. A good suggestion would be to use your "Get out of jail free" card to steal a horse in the Whiterun Stables ouside and use it to travel to faraway areas that would otherwise be too time-consuming to reach on foot.